Stoichiometry I: The Mole and Chemical Formulae - Chemistry (Undergraduate Foundation)

This course covers the foundational principles of chemical measurement. It provides a complete treatment of the mole concept, molar mass, and the determination of empirical and molecular formulae from gravimetric (mass-based) experimental data. The material also covers the essential skill of calculating solution concentrations, including molarity. A command of the mole concept is the absolute, non-negotiable foundation for all quantitative chemistry. These are the accounting principles used in every laboratory and industrial process to measure chemical substances. This knowledge is essential for preparing solutions of a known concentration and for determining the identity of an unknown compound. By the end of this course, you will be able to perform all calculations involving the mole, molar mass, and Avogadro's number. You will also be able to determine the empirical and molecular formula of any compound from its percentage composition or combustion data, and calculate the concentration of solutions in moles per dm³. This course is for students who have completed a course on atomic theory. It is the mandatory starting point for the study of stoichiometry and is a prerequisite for any further study in chemistry, chemical engineering, or the biomedical sciences.

Payment required for enrolment
Enrolment valid for 12 months
This course is also part of the following learning track. You may join the track to gain comprehensive knowledge across related courses.
[NUC Core] CHM 101: General Chemistry I
[NUC Core] CHM 101: General Chemistry I
This learning track delivers the complete NUC CCMAS curriculum for General Chemistry I. It is a comprehensive programme designed to build a robust, university-level foundation in modern chemistry. The track systematically covers all essential topics, from atomic theory, chemical bonding, and the states of matter, to the quantitative principles of stoichiometry, equilibrium, thermodynamics, and kinetics. This programme is for first-year undergraduates in science, technology, engineering, and mathematics (STEM) faculties who are required to take CHM 101. It is also essential for any student or professional globally who needs a rigorous and complete foundation in first-year university chemistry for further study or career development. This track delivers a full skill set in chemical theory and quantitative problem-solving. Graduates will be able to determine molecular structures, calculate reaction quantities, analyse the energetics and rates of reactions, and solve complex equilibrium problems. This programme provides the non-negotiable prerequisite knowledge for all subsequent chemistry courses and for any degree in the physical sciences, engineering, or medicine.

This learning track delivers the complete NUC CCMAS curriculum for General Chemistry I. It is a comprehensive programme designed to build a robust, university-level foundation in modern chemistry. The track systematically covers all essential topics, from atomic theory, chemical bonding, and the states of matter, to the quantitative principles of stoichiometry, equilibrium, thermodynamics, and kinetics. This programme is for first-year undergraduates in science, technology, engineering, and mathematics (STEM) faculties who are required to take CHM 101. It is also essential for any student or professional globally who needs a rigorous and complete foundation in first-year university chemistry for further study or career development. This track delivers a full skill set in chemical theory and quantitative problem-solving. Graduates will be able to determine molecular structures, calculate reaction quantities, analyse the energetics and rates of reactions, and solve complex equilibrium problems. This programme provides the non-negotiable prerequisite knowledge for all subsequent chemistry courses and for any degree in the physical sciences, engineering, or medicine.

Course Chapters

1. Introduction
1

This chapter provides the roadmap for the course. It introduces the mole as the central unit of measurement in chemistry and outlines the progression from counting atoms to determining chemical formulae. Key learning objectives include: understanding the overall course structure and appreciating the role of the mole concept as the foundation for all quantitative chemistry.

Chapter lessons

1-1. Welcome

This lesson provides a brief overview of the course, outlining the key topics of the mole, chemical formulae, and solution concentration.

2. The Mole Concept
2
4

This chapter covers the single most important quantitative concept in chemistry. It formally defines the mole, Avogadro's number, and molar mass, providing the essential tools for chemical accounting. Key learning objectives include: defining the mole and Avogadro's number; and calculating the molar mass of any element or compound.

Chapter lessons

2-1. Definition of mole

This lesson formally defines the mole as the SI unit for the amount of substance and introduces its relationship to Avogadro's number.

2-2. Molar mass

This lesson defines molar mass as the mass of one mole of a substance and explains how to calculate it for both elements and compounds.

3. Chemical Formulae
2
4

This chapter focuses on the methods used to determine the chemical formula of a substance from experimental mass data. It covers the distinction between empirical and molecular formulae. Key learning objectives include: defining empirical and molecular formulae; and calculating the empirical formula from percentage composition or combustion data.

Chapter lessons

3-1. Formulae definitions

This lesson defines the empirical formula as the simplest whole-number ratio of atoms and the molecular formula as the actual number of atoms in a molecule.

3-2. Percentage composition

This lesson covers the step-by-step procedure for calculating a compound's empirical formula from its percentage composition by mass.

4. Solution Concentrations
3
4

This chapter introduces the quantitative measures used to describe the composition of solutions. It focuses on the most important unit of concentration in chemistry: molarity. Key learning objectives include: defining the components of a solution; and calculating the molarity of a solution from the amount of solute and the volume of the solution.

Chapter lessons

4-1. Defining concentration

This lesson defines concentration as the amount of a solute dissolved in a given quantity of a solvent or solution.

4-2. Calculating molarity

This lesson formally defines molarity as the number of moles of solute per litre (dm³) of solution and provides the formula for its calculation.

4-3. Dilution calculations

This lesson introduces the dilution formula (M₁V₁ = M₂V₂) and explains how it is used to calculate the concentration of a solution prepared by diluting a stock solution.

5. Conclusion
2

This concluding chapter summarises the core concepts of chemical measurement. It reinforces the understanding of the mole, chemical formulae, and concentration. This summary prepares the student for the next course, 'Stoichiometry II', where these accounting tools will be applied to chemical equations.

Chapter lessons

5-1. Course summary

This lesson consolidates knowledge by reviewing the central role of the mole in converting between mass and particles, determining chemical formulae, and calculating solution concentrations.

5-2. Next steps

This final lesson looks ahead, explaining how the skills of chemical accounting are the direct prerequisite for balancing chemical equations and calculating reaction quantities.